Results 41 to 50 of about 4,343 (225)

Abstract 3-Rigidity and Bivariate $C_2^1$-Splines I: Whiteley's Maximality Conjecture

open access: yesDiscrete Analysis, 2022
3-Rigidity and Bivariate $C_2^1$-Splines I: Whiteley's Maximality Conjecture, Discrete Analysis 2022:2, 50 pp. Suppose one realizes a graph $G$ by taking its vertex set to be a set of points $x_1,\dots,x_n$ in $\mathbb R^d$ and the edge joining $x_i$ to
Katie Clinch   +2 more
doaj   +1 more source

The structure of equivalent 3-separations in a 3-connected matroid [PDF]

open access: yes, 2004
For the abstract of this paper, please see the PDF ...
Oxley, James   +11 more
core   +1 more source

$Star^1$-convex functions on tropical linear spaces of complete graphs [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2012
Given a fan $\Delta$ and a cone $\sigma \in \Delta$ let $star^1(\sigma )$ be the set of cones that contain $\sigma$ and are one dimension bigger than $\sigma$ . In this paper we study two cones of piecewise linear functions defined on $\delta$ : the cone
Laura Escobar
doaj   +1 more source

Representing Matroids over the Reals is $\exists \mathbb R$-complete [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science
A matroid $M$ is an ordered pair $(E,I)$, where $E$ is a finite set called the ground set and a collection $I\subset 2^{E}$ called the independent sets which satisfy the conditions: (i) $\emptyset \in I$, (ii) $I'\subset I \in I$ implies $I'\in I$, and ...
Eun Jung Kim   +2 more
doaj   +1 more source

Reducing the rank of a matroid [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2015
We consider the rank reduction problem for matroids: Given a matroid $M$ and an integer $k$, find a minimum size subset of elements of $M$ whose removal reduces the rank of $M$ by at least $k$. When $M$ is a graphical matroid this problem is the minimum $
Gwenaël Joret, Adrian Vetta
doaj   +1 more source

Real phase structures on matroid fans and matroid orientations

open access: yes, 2023
We introduce the notion of real phase structure on rational polyhedral fans in Euclidean space. Such a structure consists of an assignment of affine spaces over $\mathbb{Z}/2\mathbb{Z}$ to each top dimensional face of the fan subject to two conditions ...
Shaw, Kris   +2 more
core   +1 more source

Matroidal Structure of Generalized Rough Sets Based on Tolerance Relations

open access: yesThe Scientific World Journal, 2014
Rough set theory provides an effective tool to deal with uncertain, granular, and incomplete knowledge in information systems. Matroid theory generalizes the linear independence in vector spaces and has many applications in diverse fields, such as ...
Hui Li, Yanfang Liu, William Zhu
doaj   +1 more source

Graphic Splitting of Cographic Matroids

open access: yesDiscussiones Mathematicae Graph Theory, 2015
In this paper, we obtain a forbidden minor characterization of a cographic matroid M for which the splitting matroid Mx,y is graphic for every pair x, y of elements of M.
Pirouz Naiyer
doaj   +1 more source

Matroids on the Bases of Simple Matroids

open access: yesEuropean Journal of Combinatorics, 1981
Let M be a simple matroid (= combinatorial geometry). On the bases of M we consider two matroids S(M, F) and H(M, F), which depend on a field F. S(M, F) is the simplicial matroid with coefficients in F on the bases of M considered as simplices. H(M, F) has been studied by Björner in [1].
openaire   +1 more source

Towards a splitter theorem for internally 4-connected binary matroids

open access: yes, 2011
This is the post-print version of the Article - Copyright @ 2012 ElsevierWe prove that if M is a 4-connected binary matroid and N is an internally 4-connected proper minor of M with at least 7 elements, then, unless M is a certain 16-element matroid ...
Chun, Carolyn   +8 more
core   +1 more source

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